By accidents and disasters, the railway service was often suspended between Hokkaido and Honshu. In this study, path-searching model for rail freight transportation is built and is applied practical case. Since the model can search an alternative route considering the timetable, it can evaluate alternative routes involving the frequency and departure time of transportation. It can also evaluate considering the opening time at the suspended link. As a result, it is clarified that car ferry lines are effective in alternativetransportation from the viewpoint of transportation time shortening. Therefore car ferry lines should be considered as an alternative transportation for rail freight.